MotoMeter Instruments

Those who are faced with providing a kit-built or other amateur-constructed car with instruments, or manufacturers of small-production specialist cars, will be interested to know that a range of high-quality MotoMeter instruments, made in Stuttgart, Germany, are obtainable from Time Instrument Manufacturers Ltd., 37/38, Hatton Garden, London, E.C.1 (Tel.: Holborn 4255-7). These instruments are noted for precision-construction and clear dials, and are fully-illuminated. The following are available:

An ammeter in 2 in. (52 mm.) size, price 18s. 6d. retail. A 40 mm. white-dial version is also supplied.

Water temperature gauges with full scale in 2 in. size, reading 40°-120°C., for block or water-hose fitting, or with a short scale but red light that comes on at approx. 95 C., both priced at 57s 6d. retail A similar gauge with short scale and no Warning lamp is priced at 48s. 6d.

Oil-pressure gauge complete with copper tubing, union and T-piece, registering 0-100 lb./sq. in., priced at 59s. 6d. retail.

We have arranged for a set of these instruments to be tested in a Rochdale Olympic and intend to comment in due course. Besides these instruments, Time Instrument Manufacturers can supply a Mototherm inside/outside thermometer, calibrated in Fahrenheit or Centigrade, a white hand indicating inside and a red hand outside temperature. A red light indicates when outside temperature falls to freezing point. Rally drivers will find this an invaluable addition to a car’s instruments; the price complete is £5 5s. retail.

In addition, the MotoMeter car clocks with the renowned Kienzle movement are available, in 52 mm. size at £4 14s. 8d., in 60 mm. size at £4 19s. 4d., both prices inclusive of p.t. These clocks have the famouse Kienzle movement made by the Black Forest clock-makers with 185 years’ experience behind them. It is significant that Rover have adopted these quiet-running, accurate clocks for their new 3-litre cars. 80 mm. and 140 mm. clocks are also available, normally 12-volt, but 6-volt to special order.

The following claims are made for the well-known Kienzle 607 movement used in all these clocks:—

“Movement 607 has been designed especially for use in vehicles. It is a further development of the 606 movement of world-wide reputation. It consists essentially of two assemblies:—

(a) Mechanical parts (oscillating system with escapement, wheels and pinions).

(b) Electro-magnetic winding mechanism (electro-magnetic armature system and energy storage mechanism). The electro-magnetic winding mechanism functions as an electro-magnetical converter, i.e., at regular intervals electrical energy is converted into mechanical energy. A magnetic armature system extends a spring which in its turn drives the clock movement. As the force driving the clock movement is also independent of the electrical voltage, variations in the battery voltage do not affect the running of the clock. The winding mechanism is damped with plastic material and is very quiet in operation.

“The diameter of the movement is 48 mm. without the casings. The depth of the movement measured across the plates is 24.2 mm. The oscillation period of the balance is 4/9 sec. (instead of the usual 4/10 sec.) or 16,200 half-oscillations per hour. (It has been found that the longer oscillation period, producing a slower tick, is easier on the car). The balance has a moment of inertia of 0.300 g.cm. This relatively high moment of inertia reduces liability to errors from external causes. (The liability of a clock to certain errors is inversely proportional to the moment of inertia of the balance.) The balance staff is fitted with parallel pivots working in jewel bearings. The use of jewels for the balance staff ensures even running over a long period of time. In our long experience, we have found that, conical bearings wear too quickly. In particular, the material of all conical bearings known up to the present time is not suitable for balances larger than those used in wrist watches. Moreover, jewels can be mass produced to a very high degree of accuracy. The escapement of the 607 MOVC merit is robust, accurate, and reliable. The general aim in designing movement 607 has been to keep the working parts as few and as simple as possible; this factor in itself increases reliability. For example, the 607 movement has no coupling spring; instead the driving force is transmitted direct from the impulse click to the wheels and pinions. Therefore, failures in starting the movement are impossible. A flywheel coupled to a coil spring (tension), ensures that the resultant momentum remains nearly constant. Many years of experience have shown that contact failure do not occur. This is achieved on the one hand by choosing suitable materials for the contacts and having the electrical and mechanical parts of suitable proportions, and on the other hand by incorporating into the design certain special features which are individually the subject of patents.

“To provide against the possible consequences of a short circuit, a fuse is provided which, dependent on the battery voltage, breaks the circuit in a few moments. The current flowing through the coil during this time remains so small, thanks to the relatively high resistance of the coil, that it cannot cause any damage to the battery. The fuse is in the form of a rivet. This guards against failures due to the displacement of the fuse, which in our experience can arise in the ease of soldered fuses.

“A very high degree of reliability in running, not only for short periods, but for years, is obtained due to the nearly constant driving momentum, the small frictional losses in the wheel train, and the effective angle of the escapement in conjunction with the relatively high moment of inertia of the balance. Before leaving the factory, clocks fitted with the 607 movement are regulated to a high degree of accuracy. In the case of bulk deliveries the deviation is not larger than —3 to +0/5 minutes per week at normal temperature. But by far the majority show a timekeeping accuracy within 0 to + 3 minutes per week. The 607 movement is affected by temperature only to a very limited extent. Good isochronism is maintained within a temperature range of —20°C to +50°C. Naturally, at extreme temperatures, the deviation can be larger than above mentioned. The best non-resiniferous synthetic clock oils are used in movement 607. It has been found from experience that the voltage of vehicle batteries is subject to considerable variation, due on the one hand to the demands placed on the battery by the running of the vehicle at any particular moment; on the other hand to the length of time the battery has been used, and to seasonal changes in temperature. Taking this into account the 607/6-volt movement works perfectly at voltages ranging from about 2 to 9 volts and the 607/12-volt movement at voltages from about 4 to 18 volts. These are average figures. Thanks to the high electro-mechanical efficiency of the winding mechanism, the current consumption of the 607 movement (only a few thousandths of a watt), is of negligible proportions compared with that of the other current-using equipment of a vehicle. The movement is mounted within the casing on rubber cushions, thus ensuring a high degree of shock absorption. No less than 13 German and/or foreign patents cover movement 607.”

Incidentally, domestic watches and clocks of all kinds, ranging in price from 25s. to £27 18s., are also imported, and other instruments available include ribbon-action water temperature gauges measuring 2½ in. x 1 in. (63s.) carburetter synchro-resters (90s.) compression testers, and a range of tyre gauges (15s. 6d. to 35s.). VW petrol gauge kits for models after August 1960 are available at £5, and VW oil temperature gauge kits for £4.

MotoMeter instruments are used by the leading Continental car manufacturers. Time Instrument Manufacturers Ltd. will supply details on application to anyone mentioning Motor Sport. They should be of some concern to those who have experienced inaccuracy and failures in the sort of clocks and instruments fitted to many present-day cars.—W.B.

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RAPID PIT-STOP!

“One has images of the hero grinding into the pits, wiping oil off his face, breaking into a handsome grin, hugging a classy blonde and then jumping back into his cockpit and off on his reckless way to another winning glory “—Danny Blanchflower writing in the Sunday Express of Stirling Moss.